117,365 research outputs found
On Secure Workflow Decentralisation on the Internet
Decentralised workflow management systems are a new research area, where most
work to-date has focused on the system's overall architecture. As little
attention has been given to the security aspects in such systems, we follow a
security driven approach, and consider, from the perspective of available
security building blocks, how security can be implemented and what new
opportunities are presented when empowering the decentralised environment with
modern distributed security protocols. Our research is motivated by a more
general question of how to combine the positive enablers that email exchange
enjoys, with the general benefits of workflow systems, and more specifically
with the benefits that can be introduced in a decentralised environment. This
aims to equip email users with a set of tools to manage the semantics of a
message exchange, contents, participants and their roles in the exchange in an
environment that provides inherent assurances of security and privacy. This
work is based on a survey of contemporary distributed security protocols, and
considers how these protocols could be used in implementing a distributed
workflow management system with decentralised control . We review a set of
these protocols, focusing on the required message sequences in reviewing the
protocols, and discuss how these security protocols provide the foundations for
implementing core control-flow, data, and resource patterns in a distributed
workflow environment
Security and Privacy Issues in Wireless Mesh Networks: A Survey
This book chapter identifies various security threats in wireless mesh
network (WMN). Keeping in mind the critical requirement of security and user
privacy in WMNs, this chapter provides a comprehensive overview of various
possible attacks on different layers of the communication protocol stack for
WMNs and their corresponding defense mechanisms. First, it identifies the
security vulnerabilities in the physical, link, network, transport, application
layers. Furthermore, various possible attacks on the key management protocols,
user authentication and access control protocols, and user privacy preservation
protocols are presented. After enumerating various possible attacks, the
chapter provides a detailed discussion on various existing security mechanisms
and protocols to defend against and wherever possible prevent the possible
attacks. Comparative analyses are also presented on the security schemes with
regards to the cryptographic schemes used, key management strategies deployed,
use of any trusted third party, computation and communication overhead involved
etc. The chapter then presents a brief discussion on various trust management
approaches for WMNs since trust and reputation-based schemes are increasingly
becoming popular for enforcing security in wireless networks. A number of open
problems in security and privacy issues for WMNs are subsequently discussed
before the chapter is finally concluded.Comment: 62 pages, 12 figures, 6 tables. This chapter is an extension of the
author's previous submission in arXiv submission: arXiv:1102.1226. There are
some text overlaps with the previous submissio
Proof-of-Concept Application - Annual Report Year 1
In this document the Cat-COVITE Application for use in the CATNETS Project is introduced and motivated. Furthermore an introduction to the catallactic middleware and Web Services Agreement (WS-Agreement) concepts is given as a basis for the future work. Requirements for the application of Cat-COVITE with in catallactic systems are analysed. Finally the integration of the Cat-COVITE application and the catallactic middleware is described. --Grid Computing
Tiny Groups Tackle Byzantine Adversaries
A popular technique for tolerating malicious faults in open distributed
systems is to establish small groups of participants, each of which has a
non-faulty majority. These groups are used as building blocks to design
attack-resistant algorithms.
Despite over a decade of active research, current constructions require group
sizes of , where is the number of participants in the system.
This group size is important since communication and state costs scale
polynomially with this parameter. Given the stubbornness of this logarithmic
barrier, a natural question is whether better bounds are possible.
Here, we consider an attacker that controls a constant fraction of the total
computational resources in the system. By leveraging proof-of-work (PoW), we
demonstrate how to reduce the group size exponentially to while
maintaining strong security guarantees. This reduction in group size yields a
significant improvement in communication and state costs.Comment: This work is supported by the National Science Foundation grant CCF
1613772 and a C Spire Research Gif
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